Hi Appsheet community!
Got a quick question regarding Valid_If constraints on Ref fields.
In a nutshell i need to filter a Ref field based on the selection of another Ref Field.
What i’ve got:
Tables: 1) “Books” - key column = [BOOK_UID] 2) “Bookstores” - key column = [BNP_UID] 3) “Bookstore_Placement” - key column = [BKSTP_UID].
Bookstore_Placement obviously has [BOOK_UID] and [BNP_UID] as Refs.
The trick is when adding a new entry into “Bookstore_Placement”, and selecting a [BNP_UID] , to get the list of books that are NOT currently placed in that Bookstore ?
In plain English - i don’t want to place the same book twice in a bookstore. Is this possible?
It feels like i need to do something like a SELECT within SELECT … not sure…
Thanks for any suggestions or ideas…